PEPS Report Summary

Final Report Summary - PEPS (Exploring the physics of Proto-stars and Extra-solar PlanetS)

The “PEPS” project (Understanding the physics of “Protostars and Extrasolar PlanetS”) was globally devoted to star and planet formation. The project has enabled us to fully consider the complex physical processes at play in star formation, from the initial collapse of the cloud to the formation of the so-called first Larson core, namely gravity, turbulence, radiation (responsible for the cooling and heating of the gas) and magnetic field.These calculations are now at the forefront of the research in the domain and allow a detailed understanding of the very process of star formation. The calculations have also led to the resolution of the so-called “luminosity problem” of protostars by showing that accretion on nascent objects is episodic and can lead to much compact objects, thus much lower luminosities than previously expected. These calculations provide a consistent paradigm for the observable properties of young, accreting objects. During the project, we have also developed a preliminary set of calculations of atmosphere models typical of cool objects - brown dwarfs and exoplanets - including the formation of molecules and condensates (grains) and the interplay with turbulent motions in the atmosphere. Eventually, this will lead to the reliable characterization of the fundamental properties of brown dwarfs and extrasolar planets (mass, radius, composition, temperature) in terms of their observable properties (emergent spectrum, luminosity) over the entire relevant mass range.